The present invention relates to a probe which is preferably used in, for example, a pulse oximeter for optically measuring the arterial oxygen saturation.
A pulse oximeter is an apparatus for measuring the arterial oxygen saturation in living tissue based on a ratio of the intensity of transmitted light which has been transmitted through the living tissue, to irradiation light which irradiates the living tissue. When measurement is to be performed, a probe including a light emitting section having a light source and a light receiving section for converting the received light to an electric signal the level of which corresponds to the intensity of the received light is attached to the finger or the like.
As such a probe, for example, there is a probe which is disclosed in JP-A-2003-225215. The probe includes a supporting member which has a substantially band-like shape in order to be wrapped around the finger or the like, and light emitting and receiving sections which are attached to the supporting member. In the state where the supporting member is wrapped around the finger or the like, the probe can be attached to the finger or the like by bonding through an adhesive surface which is provided on the supporting member.
In such a probe, in order to prevent the supporting member, which is relatively hard, from being in direct contact with the finger or the like, when the probe is attached to the finger or the like, a soft material such as a sponge is attached to a surface of the supporting member which is to be in contact with the living body. The supporting member and the sponge have a substantially same width. Depending on the manner or the place of attaching the supporting member, therefore, end portions of the supporting member may be in direct contact with the skin of the attachment place to press the place. In the case where such a probe is attached to the finger or the like of a premature infant or neonatal infant the skin of whom is weak, when the supporting member is in direct contact with the skin, particularly, there is a possibility that the skin of the attachment place is damaged.